Because (in relation to the article) we're talking about companies and social groups making decisions, not just the govt. Notably, I think the US 1st amendment is basically based around the idea that we, collectively, will take social action above the personal level. If you remove that ability, my defense of the 1st amendment reduces notably.

I see the social discourse primarily being improved by the general awareness that it CAN be harmed. To think it's immune from harm outside of censorship is the key problem.